Ethereum flash loan
In my opinion, we can start with mainstream value currencies such as BTC now. Judging from the trend of BTC in the past year, it is basically at the bottom now. Even if it is possible to fall further, it will not fall too much. Ten years of history shows that BTC is certainly valuable, and BTC will definitely appreciate in the future. After all, it is the gold of the currency circle, which is rare and has the greatest consensus. The above is just a personal statement and does not constitute an investment proposal. Investment should be cautious! Finally, I declare that if you lose money by investing in virtual currency, I will not bear any legal responsibility
in China, the other one I know is the network mutual aid blockchain, which represents the platform of concentric mutual aid. Blockchain technology is used to solve the shortcomings of the network mutual aid instry. At present, blockchain is also very popular in the network mutual aid instry.
at present, the vast majority of digital currency transactions are concted in exchanges. Among the numerous exchanges, bitfinex, binance, okex and so on are well-known
However, bitcoin and other digital currencies, as decentralized assets, have to be traded in a centralized exchange, which seems to have hidden contradictions and dangers1. Problems and challenges of stock exchanges=“ //www.yuanxue365.com/en/img_fd039245d688d43fdf16c83b761ed21b0ff43bbf ">
in February 2014, Mt. GOx, the world's largest bitcoin exchange at that time, was stolen 850000 bitcoins, and the price of bitcoin suffered a" cliff "crash on that day. Later, it was revealed that Mt. GOx was in fact a thief, and only 7000 bitcoins were actually stolen
in August 2016, bitfinex, the largest U.S. dollar bitcoin trading platform, suffered a security vulnerability, resulting in the theft of 120000 bitcoins, which was worth $65 million at that time. If converted into the price in December 2017, it would be worth nearly $2 billion
on December 19, 2017, South Korea's youbit exchange was attacked by hackers and lost 4000 bitcoins, and the exchange declared bankruptcy
on December 21, 2017, the Ukrainian liqui exchange was stolen 60000 bitcoins, and the unit price of bitcoin plummeted by US $2000
in 2018, such a drama will only continue
in addition to the threat of hackers, traditional exchanges also have some inherent shortcomings, such as lack of supervision and inefficiency. The security of the exchange for investors can only rely on its own credit, and the cost of running is very low. The stock exchange is regulated at the national level, but there is no such sword of Damocles on the top of the digital currency exchange. Moreover, in an exchange, the same order can only be submitted to one exchange. After the user places an order, the funds used for the transaction will be frozen and can only wait for the completion or cancellation of the transaction. These are undoubtedly inefficient
All in all, the problems of exchanges are the problems of centralization2. Decentralization of exchanges=“ //www.yuanxue365.com/en/img_86d6277f9e2f070889a173c9e224b899a801f257 ">
(1) the progress of the exchange itself
the upgrade of security means is various. At present, the best use is cold wallet, that is, to keep the digital currency in the offline U disk. At the end of 2017, when the YouTube exchange was attacked, 75% of its assets were withdrawn into the cold purse in time to avoid greater losses. However, it seems to be a helpless way to protect the online assets by offline means. Of course, there should be many other methods, which will not be repeated here
(2) the representative of cross ledger transaction is ripple network, and the operating company is ripple labs, which is a semi centralized system. Ripple is a decentralized clearing agreement. In order to solve the high cost and delay of inter-bank clearing, its base currency is XRP. Ripple network can connect all kinds of assets, such as US dollar, RMB, Japanese yen, bitcoin, etc. to its own network. In this system, U.S. dollars or bitcoin can be converted into reborn currency, and then reborn currency can circulate freely in the network, just as a highway is built between various assets. Due to the support of major banking institutions, the reborn currency achieved nearly 300 times growth in 2017
(3) decentralized exchange
some teams try to use blockchain technology to build a decentralized exchange. This kind of decentralized exchange, to some extent, is an extension of cross ledger trading
bitshares is the most representative of early rising projects. It builds a blockchain development platform with servers scattered all over the world. Even if some of them are attacked, the system will not collapse. Anyone can transfer money and borrow money freely on this platform, and can also quickly build a centralized exchange based on this platform. In order to ensure stable value, bitstocks also require three times of digital assets as collateral. At present, bitstocks are running fairly well
later, with the development of Ethereum and smart contract, the x x protocol came into being. This is an open protocol running in the Ethereum blockchain and a decentralized exchange in the Ethereum ecosystem. The agreement has attracted many investors. At present, it has completed financing and started to build open source software tools and infrastructure. Of course, there are many competitors. Ether Delta, IDEX and oasis DEX are trying to provide similar functions. Moreover, it is a smart contract system based on Ethereum, which only supports erc20 token. If other smart contract public chains start to rise, the demand will be reced
in addition, there are some teams that are entering, such as the domestic road seal agreement, looping (LRC) in English. They adopted a design similar to the X protocol, and also introced a fast payment function similar to the lightning network. It is characterized by trying to match multiple exchanges, the user's order can be broadcast to multiple exchanges, and completed by different exchanges. Moreover, the user can still use the account funds after placing an order, and the user's behavior of transferring part or all of the funds is equivalent to partial or total cancellation. To some extent, it improves the breadth and timeliness of the transaction. However, this system seems to have damaged the "power" of the existing exchanges. Whether we can persuade everyone to play together will be a difficult problem
At present, there is still a long way to go for the construction of decentralized exchange. In 3-5 years, traditional exchange will still be the main battlefield of digital currency However, in the future, it is worth looking forward to let the decentralized digital currency get rid of the shackles of centralizationThe application prospects of blockchain are mainly in the fields of finance, Internet of things and logistics, public services, digital rights and insurance
1. Blockchain has great potential applications in international exchange, letter of credit, equity registration, stock exchange and other financial fields. The application of blockchain technology in the financial instry can eliminate the third-party intermediary link and realize the point-to-point direct docking
2. Blockchain can also be naturally combined in the field of Internet of things and logistics, which is considered as a promising application direction of blockchain. The establishment of credit resources in the blockchain can double improve the security of transactions and improve the convenience of Internet of things transactions. It can save time and cost for the application of intelligent logistics mode
3. Blockchain is closely related to people's proction and life in public management, energy, transportation and other fields. The decentralized and fully distributed DNS service provided by blockchain can realize the query and resolution of domain name through the point-to-point data transmission service between nodes in the network
4. Through blockchain technology, works can be authenticated to prove the existence of text, video, audio and other works and ensure the authenticity and uniqueness of ownership. After the works are confirmed on the blockchain, the subsequent transactions will be recorded in real time to realize the full life cycle management of digital rights, and can also be used as a technical guarantee in judicial evidence collection
5. In terms of insurance claims, insurance institutions are responsible for fund collection, investment and claims settlement, and often have higher management and operation costs. Through the application of smart contract, there is no need for the applicant to apply or the insurance company to approve. As long as the claim conditions are triggered, the automatic claim settlement of the policy can be realized
extended data:
the core technology of blockchain
1. Consensus mechanism, through the voting of special nodes, completes the verification and confirmation of transactions in a very short time; For a transaction, if several nodes with unrelated interests can reach a consensus, it can be considered that the whole network can also reach a consensus. The goal of blockchain consensus mechanism is to make all honest nodes keep consistent blockchain views
2. Asymmetric encryption requires two keys for encryption and decryption, which are public key and private key. The public key corresponds to the private key. The public key is used in the process of data encryption, and only the corresponding private key can be used to decrypt; On the contrary, the private key is used to encrypt the data, and only the corresponding public key can be used to decrypt the data
I hope I can help you:
webpage link
abey blockchain technology is from Ciprian pungela & amp; Co., two doctors in the Department of artificial intelligence from the Department of computer science, School of mathematics and information, Western University of timishwara, Romania; Vorel negru's own research project. Constant lightweight blockchain technology and multi-layer programming and extended blockchain solution are adopted. The scale of abey's blockchain remains unchanged, with only 50 active blocks. Abey blockchain technology is suitable for the use of e-money in e-commerce system for mass transactions, and has multi-level, scalability and security, and can be programmed
according to the official white paper, abey is suitable for the blockchain solution in e-commerce system, which uses digital currency to carry out mass transactions and can carry out multi-layer programming and expansion
specific implementation method of abey blockchain Technology:
using a multi-level and programmable blockchain method to realize digital currency (for simplicity, we call it "DC"). This method can pave the way for the implementation of various e-commerce purposes, such as loan financing, completion of refundable transactions and non refundable transactions. In the first layer of the blockchain, we can realize the inherent digital currency design, which is commonly referred to as the base layer ("FL"). The various upper layers built on this foundation can be used to describe various additional functions related to various business driven application examples (which we will briefly introce below). All of the above levels are fully programmable, and can be easily adapted for various applications
although most of today's digital goods store transaction balance in the blockchain, abey's method is more similar to Pascal coin digital currency. This method uses what we call a "vault" encryption structure“ The "vault" structure can only save the balance of all accounts in the network, instead of a complete list of all completed transactions, and can be reconstructed in the evolution history of the blockchain. Since vault allows the deletion of useless content at any time, it can significantly rece the storage cost of blockchain. In contrast, at the time of writing this article, the storage space required to download bitcoin database is 70gb (the alarm rate is still growing, and it is expected to reach 300gb in 2019), so it is not feasible to use ultrabooks or notebooks with small storage space (such as 120GB or 256gb) to carry out mining operation. On the other hand, the size of the abey blockchain will remain unchanged, with only 50 blocks (at the time of writing, there are more than 525000 blocks in the bitcoin blockchain)
vault fully supports digital currency transfer between accounts. In addition, vault can assign an owner defined name to each account instead of using hashing algorithms like today's cryptocurrency - which makes the account easier to remember and makes the name public
one of the important functions that vault can help prevent the daily expenses of blockchain from being too high (especially those related to transaction history) is that vault can save such states and rece the size of blockchain itself by creating a secure of blockchain states. Because there is no transaction history and all accounts can save their direct balance, the blockchain information has the feature of partial erasure. All the blockchain states that can be stored can be regarded as landmarks of the blockchain
secure data sharing:
through the block chain structure design, for each transaction sent to the network, the block chain may contain encrypted metadata. The metadata can only be decrypted by the transaction recipient. For the transaction sent to the network, the sender's public key is included in the transaction, and the transaction receiver decrypts the metadata using the public key. Since the transaction receiver holds the private key for decryption, only the transaction receiver can implement the data decryption process. From the perspective of encryption method, although bitcoin is limited to elliptic curve cryptography, blockchain metadata can use any other encryption mechanism to complete the encryption process. This not only provides complete flexibility in security selection, but also does not have any adverse impact on the structure or function of the blockchain
scalability:
since the abey blockchain supports the creation of historical landmarks by design, it is very easy for the network itself to achieve high scalability from the point of view that the blockchain will always need to store (related to the latest existing SLS). This method completely eliminates the need to store transaction history to calculate the balance of all accounts, and can directly store all account balances, so as to ensure that the specific balance information provided by all nodes in the network meets the requirements of Byzantine consistency
proof of security and workload:
it is impossible to have two-way payment operation in abey's method (in the specified appropriate scenario, the vast majority of today's mainstream cryptocurrencies may theoretically have two-way payment operation). Each transaction means that the balance of the corresponding account is updated in a relatively simple way, and there is no special way to restore the transaction from the network pending transaction team. For the abey blockchain, since all technical / functional layers are built on vault, vault is the infrastructure of our blockchain, so vault is very important for mining operations. Our proposed blockchain model is composed of a series of blocks, each of which is generated by the nodes in the network who are willing to mine. All nodes in the network can update the account balance independently according to the transaction (part of the block), and are independent of other nodes. The mining operation will affect the first functional layer. In addition to updating the balance, each node can also update other matters that may belong to the upper functional layer in the composition of the blockchain structure. Once an update occurs, a new mining incentive block will be created. The mining reward block contains a number of new reward accounts that have been assigned to miners. The miner is the winner of the above reward according to the workload Certificate (currently there are 50 reward accounts). The way to reward is to distribute the public key of all such accounts to the reward recipient
blockchain technology layer:
abey's digital currency model contains a multi-layer structure, in which the first layer represents the realization of the digital currency itself (see Figure 7 for graphic explanation). The corresponding levels include:
tier 1 → digital currency (cryptocurrency): currency transfer, mining
tier 2 → refundable transaction and non refundable transaction: allowing the use of digital justice system to complete refundable transaction
Tier 3 → related parties and commission: allowing the automatic distribution of Commission to related parties
Tier 4 → contacting currency: by lending currency, Income based on interest
layer 5 → programmable: reserved for future realization of Turing complete programming model, so as to process blockchain data in a customized way (such as smart contract)
layer 6 → custom protocol: reserved for future use
transaction type:
abey mode allows different levels in blockchain through design, Complete a variety of transaction types. The transaction types in the second layer are as follows:
1 → fund transfer: fund transfer between accounts (1-to-1 transfer)
2 → refundable fund transfer: refundable transaction between accounts. Use escrow balance instead of regular account balance
3 → key change: change the key that can be used to process the account
4 → restore the account: recover funds from the lost and invalid account
5 → set account name: define the name of the account held by the founder
6 → sales preparation: mark the account for sale
7 → move out of the sales queue: remove the account sales mark, And the account is marked as non saleable
refundable transaction and mediator:
for the vast majority of cases, non refundable transaction is equivalent to all "pay to pay" transactions in blockchain based digital currency mode. But abey has introced the concept of refundable transactions into its digital currency model. In abey mode, the transaction marked with small flag belongs to refundable or non refundable transaction. In addition, in abey's blockchain network, each account contains two types of balance: regular and unchangeable balance (used to mark the amount that the account has received and can be paid immediately, but cannot be recovered after the payment) and escrow balance (including the transaction list marked as refundable transaction and the minutes of each transaction)
8 → payment dispute: for the corresponding transaction that has been marked as a refundable transaction, the payment dispute can be initiated only by the payer
9 → refund request: for the corresponding transaction previously marked as a refundable transaction, a refund request can be initiated, but only by the payer
10 → cancel escrow: cancel the escrow funds and return the funds to the payer immediately. It can only be initiated by the payee
11 → release trusteeship: release the trusteeship fund and add the amount to the balance of the payee's account immediately. It can only be initiated by the payer
related parties and commissions:
one of the important deficiencies in today's blockchain driven financial technology is the lack of the ability to provide rewards to related parties who sell specific procts or services. The third layer of abey blockchain can solve this problem< Lending digital currency:
lending digital currency is not only a simple and quick way to allow people to borrow legal tender, but also to ensure the security of encrypted assets. Given that today's valuable digital currencies are also used for transactions, the reason why lending digital currencies is feasible is not only that it allows borrowers to mortgage any type of cryptocurrency they save, but also that it is attractive because it is a way to retain their digital assets in a completely safe or very low-risk way. In addition, abey's model also provides built-in protection through the customer vault lending gateway (VLG), and enables the VLG to act as a buffer between the lender and the borrower
12 → borrowed funds: the borrower initiates transactions in the network, announces the intention of borrowing funds, and specifies the VLG account of the borrowed funds. The transaction is similar to depositing the balance of the regular / escrow account in the selected VLG account
13 → return of collateral: the transaction is initiated by the VLG itself. VLG will return the collateral to the borrower in accordance with the risk management policy
14 → loan repayment: the transaction is initiated by the borrower. If VLG accepts repayment of the loan in digital currency, the borrower may choose to repay the loan in digital currency. Under this condition, the digital monetary fund will be converted into VLG regular account balance<
programmable blockchain:
with its associated metadata payload, the layer of blockchain can be retained to allow the further creation of intelligent contracts between peers in the network by executing the grammar based "complete Turing basic programming language" according to the original blockchain data processing mode. For each payload, encryption or public visibility processing can be implemented, and can be performed in a dedicated virtual environment (similar to a virtual machine). This method can effectively protect data security and avoid the impact of data destruction and security vulnerabilities. The main advantage of this method is that this layer can create and enforce digital contracts without any blockchain specific programming. For Ben
abey blockchain technology is from Ciprian pungila & amp; Co., Ltd., two doctors in the Department of artificial intelligence, Department of computer science, School of mathematics and information, Western University of timishwara, Romania; Vorel negru's own research project. Constant lightweight block technology and multi-layer programming and extended blockchain solution are adopted. The scale of abey's blockchain remains unchanged, with only 50 active blocks. Abey blockchain technology is suitable for the use of e-money in e-commerce system for mass transactions, and has multi-level, scalability and security, and can be programmed
analysis of abey blockchain Technology
he was elected a member of the Royal Society of England in 1756 and President of the American Philosophical Society in 1769. In 1772, he was also elected a foreign academician of the French Academy of Sciences
he is one of the founders of the United States of America. During the American War of independence, he took an active part in the anti British struggle. He was elected to the Second Continental Congress and participated in the drafting of the declaration of independence. He was sent to France from 1776 to 1785, which led to the establishment of the alliance between the United States and France. In 1787, he was elected as the representative of the constituent assembly and participated in the drafting of the constitution of the United States. He actively advocated the abolition of slavery
Franklin is the first American scientist to enjoy international reputation in the field of pure science and the pioneer of electrical research in the United States. His research on electricity unified the confused knowledge of electricity at that time. His main contribution is to expound the theory of various electric phenomena (such as the generation of charge, the transfer of charge, electrostatic inction, etc.). At first, he was keen on the invention and design of small devices, which laid a solid foundation for his future electrical experimental research. In less than 10 years since 1745, he has carried out various bold new electrical experiments with some simple tools and instruments. Through experiments, Franklin first put forward an important hypothesis in the history of electricity: the theory of electric single fluid. For the first time, Franklin used the concept of positive and negative in mathematics to express the properties of two kinds of charges; At the same time, the tip discharge phenomenon was also found. More importantly, Franklin proposed the theory of electric transfer. Later, the theory developed into the law of conservation of charge, which is one of the most basic laws in nature. In 1747, Franklin studied the Leiden bottle and explained the principle of capacitor. From 1749 to 1751, Franklin carefully observed and studied the formation of thunder, lightning and cloud, and proposed that the lightning in the cloud had the same electrical properties as the friction proced by Franklin's kite experiment. In 1750, the proposal of lightning rod was put forward. This proposal was first applied in the University of Mali in 1852. In 1752, he carried out the world shaking electric kite experiment in Philadelphia, which proved his idea of "the identity of lightning and static electricity". Franklin also studied the mutual attraction and repulsion between charged bodies; The charge distribution in the irregular charged conctor; Inction electrification, etc. Franklin coined many terms for electricity. Franklin studied and observed natural phenomena quite extensively. He also expounded the theory of heat conction; The method of obtaining low temperature by evaporation has been studied; Modern ventilation methods; Transplantation of various plants; Prevention and control of infectious diseases; The measurement of velocity and temperature in the Gulf of Mexico and the direction of storm movement in North America. Franklin's famous inventions include rocking chair, bifocal glasses, Pennsylvania stove, overhead bookshelf and so on
in philosophy, Franklin supported Deism and acknowledged the existence and objectivity of nature. He was also the first one to consciously use labor time to determine the value of proction. Franklin predicted that the population of the United States will increase geometrically, doubling on average every 25 years. This prediction has been confirmed by the census of the United States government in the last century. Franklin's works and papers on electricity include: "experiment and observation of electricity", "opinions and speculation on the properties and effects of conctive materials", "experiment and observation of electricity in Philadelphia", "on the identity of lightning and static electricity", etc.
Benjamin Franklin -- the most perfect representative of the spirit of capitalism, the greatest scientist, famous statesman and writer in the 18th century. The most authentic portrayal of his life is his own saying: "honesty and diligence should be your permanent partner."< In 1736, Franklin was elected secretary of the Pennsylvania State Council. In 1737, he was the Deputy postmaster of Philadelphia. Although the work became more and more arous, Franklin kept on studying every day. In order to further open the door to the treasure house of knowledge, he assiously studied foreign languages and successively mastered French, Italian, Spanish and Latin. He has widely accepted the advanced achievements of world science and culture. They have laid a solid foundation for their own scientific research
Frank is not only an excellent scientist, but also an outstanding social activist. He spent a lot of time in social activities in his life. Franklin attached great importance to ecation. He set up libraries, organized and founded many associations to improve the cultural quality of people from all walks of life
while he was making new achievements in scientific research, the national liberation movement in the North American colonies was on the rise e to the brutal rule of the British colonists. For the sake of national independence and liberation, he resolutely put down the experimental instruments and actively stood in the forefront of the struggle. From 1757 to 1775, he went to Britain several times as a representative of the North American colonies to negotiate. After the outbreak of the war of independence, he participated in the Second Continental Congress and the drafting of the declaration of independence. In 1776, at the age of 70, Franklin went abroad to France and won the support of French and European people for the war of independence in North America. In 1787, he actively participated in the work of making the constitution of the United States and organized the movement against slavery of black people.